Remove triple detection from cmake.

This isn't actually used for anything, and is broken on Darwin
(currently causing build failures now that the triple is passed to aid
cross compiling). Rather than fix unused code, just remove it.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@226243 91177308-0d34-0410-b5e6-96231b3b80d8
(cherry picked from commit cbc84977aa0e3b73bff718e806e2ca1e43870a81)

Change-Id: I734aa3065ef7ece0c6582b3f00674e61171ea358
2 files changed